Dynamic Scrolling Text box

I am designing a small animation for a chiropractic website and I can’t for the life of me get my dynamic text box to create the scoll bars using the UI Scrollbar, I see it sitting there but only when I set it to input text will the scrolls pop up, am I doing something wrong or does there need to be action script in that bar?

Is pretty basic the entire animation is within a movie clip, there are 20 buttons for the 20 bones each button has this code

on(rollOver){bone = "Bone 1: Blah blah blah And more info now Couple enters maybe some more and try this"}

The dynamic box is name bone_txt with the bone var. The UI scroller has bone_txt under its instance, with no additional code anywhere else.

Only thing I notice is all the buttons don’t have an instance name but that won’t change anything under the variables.